Turbocharged compressor

ABSTRACT

A turbocharged compressor system using an Organic Rankine Cycle system to recover waste heat from a compression process. The Organic Rankine Cycle system circulates an organic fluid through an evaporator, where the organic fluid vaporizes and is expanded in a turbine section of a turbocharger to drive a compressor section of the turbocharger. The organic fluid vapor is condensed in a condenser and is pumped to the evaporator once again for recirculation. The compressor section of the turbocharger pre-compresses a working fluid before entering an airend in a compression system. As the working fluid exits the airend, it may be delivered to the evaporator, where the waste heat from the working fluid evaporates the organic fluid flowing in the Organic Rankine Cycle system. The working fluid may also be circulated between intercoolers in multi-stage compressor systems.

The present application is a continuation of U.S. patent applicationSer. No. 17/523,521, filed Nov. 10, 2021, and titled “TURBOCHARGEDCOMPRESSOR”. U.S. patent application Ser. No. 17/523,521 is hereinincorporated by reference in its entirety.

BACKGROUND

Compressors are mechanical devices that increase the pressure of a fluid(e.g., air) by reducing the volume of said fluid. The temperature of thefluid increases as it is compressed.

DRAWINGS

The Detailed Description is described with reference to the accompanyingfigures. The use of the same reference numbers in different instances inthe description and the figures may indicate similar or identical items.

FIG. 1 is a perspective view illustrating a turbocharged fluidcompressor system having a waste recovery system in accordance withexample embodiments of the present disclosure.

FIG. 2 is a schematic view of a turbocharged fluid compressor system,such as the turbocharged fluid compressor system shown in FIG. 1 ,including a contact-cooled compressor having a coolant circulationsystem.

FIG. 3 is a schematic view of a turbocharged fluid compressor systemincluding a coolant-free compressor having a first compression stage anda second compression stage in accordance with example embodiments of thepresent disclosure

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of thesubject matter, reference will now be made to the embodimentsillustrated in the drawings and specific language will be used todescribe the same. It will nevertheless be understood that no limitationof the scope of the subject matter is thereby intended. Any alterationsand further modifications in the described embodiments, and any furtherapplications of the principles of the subject matter as described hereinare contemplated as would normally occur to one skilled in the art towhich the subject matter relates.

Overview

Fluid compressor systems are widely used in a variety of industries suchas in construction, manufacturing, agriculture, energy production, etc.As fluid compressors compress a working fluid, heat is produced as aresult of the pressure increase in the working fluid. This heat is notonly a waste of energy but also a waste of money for the users. Somesystems use a portion of this heat waste in energy recovery systems thatdeliver hot water as a byproduct, but not all compressor users have aneed for hot water.

Accordingly, the present disclosure is directed to a turbocharged fluidcompressor system having a waste heat recovery system that increases theefficiency of a fluid compressor system by recovering heat produced inthe compression process and using it to power a turbine section in aturbocharger. The turbocharged fluid compressor system can be used withany type of fluid compression device and should not be limited to theillustrative fluid compressor system shown in any of the accompanyingfigures. The term “fluid” should be understood to include anycompressible fluid medium that can be used in the fluid compressorsystem as disclosed herein. It should be understood that air is atypical working fluid, but different fluids or mixtures of fluidconstituents can be used and remain within the teaching of the presentdisclosure. Therefore, terms such as fluid, air, compressible gas, etc.can be used interchangeably in the present disclosure. For example, insome embodiments it is contemplated that ambient air, a hydrocarbongaseous fuel including natural gas or propane, or inert gases includingnitrogen or argon may be used as a primary working fluid.

The waste heat recovery system may comprise an organic Rankine cycle(ORC) system operating with an organic compound. One benefit of using anorganic compound in a Rankine cycle system is that it allows therecovery of heat from relatively low temperature sources such as in thecase of industrial waste heat. It should be understood that the terms“organic compound” and “organic fluid” are used interchangeably hereinto describe an organic, high molecular mass fluid, having a boilingpoint at a lower temperature than the boiling temperature of water.Although an ORC system is discussed herein, it should be understood thatthe working fluid for the Rankine Cycle in the waste heat recoverysystem may be water, or another fluid (e.g., having a low molecularmass) not classified as an organic compound. The working fluid of theRankine Cycle may have a boiling point at a lower, higher, or equal tothe boiling temperature of water.

The ORC system includes a pump to move the organic fluid within thesystem. At least one evaporator evaporates the organic fluid in thesystem, which is then directed to the turbocharger. In the ORC systemdescribed, the turbine section of the turbocharger acts as an expanderdevice to expand the organic fluid vapor and drive a compressor sectionof the turbocharger. After the organic fluid vapor exits theturbocharger, it is directed to a condenser. The condenser condenses theorganic fluid vapor, which is pumped by a pump back into the at leastone evaporator to restart the cycle.

The compressor section of the turbocharger pre-compresses a workingfluid (e.g., ambient air) before entering the fluid compressor system.The working fluid may flow through a filter device before entering thecompressor section of the turbocharger. The fluid compressor system mayinclude a positive displacement compressor such as a rotary screwcompressor or a reciprocating compressor, or a dynamic compressor suchas a centrifugal compressor or an axial compressor. The fluid compressorsystem can include a compressor with multi-stage compression or acompressor with single stage compression. Other forms and configurationsof compression devices are also contemplated herein.

As the working fluid is compressed in the fluid compressor system, thetemperature of the working fluid increases. In example embodiments, thehot working fluid may be directed to the at least one evaporator of theORC system, where the waste heat of the working fluid is used toevaporate the organic fluid of the ORC system that powers the compressorsection of the turbocharger. By using a pre-compressed fluid at an inletof the fluid compressor system, the power consumption of the fluidcompressor system improves. Thus, the efficiency of the fluid compressorsystem (e.g., the compressor section of the turbocharger) is improved byrecovering a portion of the waste heat produced as a by-product of theworking fluid's pressure increase. Additional benefits include but arenot limited to a lower pressure ratio across an airend's inlet andoutlet, which results in reduced internal leaking, and lower coolingloads entering the fluid compressor's cooling sections, both of whichfurther improve the efficiency of the fluid compressor system.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

Referring generally to FIGS. 1 through 3 , turbocharged fluid compressorsystems are described. Turbocharged fluid compressor system 100 includesa waste heat recovery system 102 and a fluid compressor system 104.Waste heat recovery system 102 includes a turbocharger 110 having aturbine section 112 and a compressor section 114. Waste heat recoverysystem 102 further includes a pump 106, at least one evaporator 108, anda condenser 116.

Pump 106 moves a waste heat recovery fluid through the waste heatrecovery system through the at least one evaporator 108, where itevaporates into waste heat recovery vapor. The waste heat recovery vaporenters the turbine section 112 of the turbocharger 110. The turbinesection 112 extracts energy from the waste heat recovery vapor andconverts it into kinetic energy, driving the compressor section 114 ofthe turbocharger 110. As the waste heat recovery vapor exits theturbocharger 110, it is directed to the condenser 116, where itcondenses.

As shown, the fluid compressor system 104 includes an inlet air filter118, a primary motive source 90, an airend 120, and an after cooler 124.Inlet air filter 118 filters the incoming working fluid (e.g., ambientair) prior to entering the pre-compression stage at the compressionsection 114 of the turbocharger 110. As the working fluid ispre-compressed, its temperature increases. A heat dissipating devicesuch as finned tube 122 shown may be installed between thepre-compression stage at compression section 114 and airend 120. Finnedtube 122 enables cooling of the working fluid and minimizes a drop inpressure. It should be understood that other types of heat dissipatingdevices for lowering the temperature of the working fluid withoutreducing the pressure accumulated during the pre-compression stage maybe used instead. For example, the heat dissipating device may be a tubewith integral external fins, a tube with integral internal fins, a tubewith a static mixer insert, etc.

The working fluid is further compressed in the airend 120. Primarymotive source 90 is operable for driving the airend 120 via a driveshaft. Primary motive source may be an electric motor, an internalcombustion engine, a fluid-driven turbine, or the like. Airend 120increases the pressure of the working fluid, which also increases thetemperature of the working fluid as a result. This hot working fluid isdirected to the at least one evaporator 108, where the waste heat isused to evaporate the waste heat recovery fluid flowing through thewaste heat recovery system 102. Upon leaving the at least one evaporator108, the pre-cooled working fluid flows into an after cooler 124, whereits temperature is further reduced prior to delivery.

With respect to FIG. 1 , an example embodiment of a turbocharged fluidcompression system 100 is shown. A structural base 50 can be configuredto support at least portions of the turbocharged fluid compressionsystem 100. In example embodiments, the turbocharged fluid compressionsystem 100 is not supported by structural base 50, with the differentcomponents forming the turbocharged fluid compression system 100 beinginstalled separately and being connected through the respective piping.An inlet ORC fluid manifold and an outlet ORC fluid manifold (not shown)may supply the ORC system with the ORC fluid needed.

FIG. 2 is a schematic of the example embodiment of the turbochargedfluid compression system 100 shown in FIG. 1 . The fluid compressorsystem 104 includes a contact-cooled airend 120 having a coolantcirculation system 136. For example, a coolant circulated by the coolantcirculation system 136 used in the turbocharged fluid compressor system100 may be oil, water, or any other coolant used in contact-cooledcompressor systems. In the contact-cooled airend 120, coolant isinjected into compression cavities within the airend to aid cooling ofthe working fluid. A discharge stream of pressurized working fluid andcoolant mixture is discharged from the contact-cooled airend 120 at ahigh temperature. The discharge stream is directed to a separator tank126, where the coolant is separated from the working fluid. Thecoolant-free working fluid is cooled at the after cooler 124 locateddownstream from the separator tank 126 prior to exiting through anoutlet 134 towards an end use machine, a compressed fluid system, or astorage tank (not shown).

After being separated from the working fluid and discharged from theseparator tank 126, the hot coolant is directed to a primary temperaturecontrol valve (TCV) 130. The primary TCV 130 is further connected to thecontact-cooled airend 120, the at least one evaporator 108, and asecondary TCV 132. The primary TCV 130 can control and selectably directthe coolant flow in the coolant circulation system towards the at leastone evaporator 108 or the airend 120 based on the desired temperature ofthe coolant flow. The primary TCV 130 directs the hot coolant dischargedfrom the separator tank 126 to the at least one evaporator 108, wherethe organic fluid absorbs the waste heat in the coolant. The at leastone evaporator 108 may be a brazed plate heat exchanger, but any othertype of heat exchanger may be used to absorb heat from the hot coolantand evaporate the organic fluid according to example embodiments of thepresent disclosure. In example embodiments, the turbocharged fluidcompressor system may have a different number of TCVs and is not limitedto having a primary and a secondary TCV. For example, a turbochargedfluid compressor system may have one TCV or may not include any TCVs.

As the cooled coolant exits the at least one evaporator 108, it flowsinto the secondary TCV 132. The secondary TCV 132 selectably directs thecooled coolant to a cooler 128 for further cooling or back into theairend 120 through the primary TCV 130, depending on the desiredtemperature of the coolant prior to entering the airend 120. Since themajority of the hot coolant's heat is absorbed in the at least oneevaporator 108, a smaller cooler 128 may be used in place of largercoolers in typical contact-cooled compressor systems. The space savedfrom the use of the smaller cooler 128 may be used to accommodate otherelements of the turbocharged fluid compressor system 100 (e.g., thecondenser 116) without significantly increasing the size of theturbocharged fluid compressor system 100 compared to other fluidcompressor systems.

Example embodiments of the turbocharged fluid compressor system 100 mayalso include a heat waste recovery system 102 that further recoverswaste heat from the compressed working fluid prior to entering theaftercooler 124, and not only recovers the waste heat from the coolantejected from the airend 120. In example embodiments, the at least oneevaporator 108 recovers the waste heat from the discharge streamcontaining the working fluid and coolant mixture prior to entering theseparator tank 126.

The turbocharged fluid compression system 100 may include a controller(not shown) operable for controlling the primary motive source 90, pump106, valves and fluid control mechanisms (e.g., the primary andsecondary TCVs), the waste heat recovery system 102 and the fluidcompressor system 104.

When the turbocharged fluid compressor system 100 is switched on, thecontroller starts the primary motive source 90, which drives the airend120. The airend 120 starts delivering the pressurized stream of workingfluid and coolant. As the discharge stream of pressurized coolant andworking fluid discharged by the airend 120 builds up in the separatortank 126, coolant separates from the working fluid in the separatortank. As the temperature of the working fluid increase, the coolant'stemperature increases. The primary TCV 130 selectably lets the hotcoolant flow into the cooler 128. Depending on selected temperatureparameters, as the coolant reaches a specific temperature, the pump 106in the ORC system 102 starts pumping organic fluid. Preferably, acoolant temperature threshold at which the pump 106 starts pumpingorganic fluid is higher than the coolant temperature threshold at whichthe primary TCV sends the separated coolant into the cooler 128. Whilethe coolant temperature does not reach the coolant temperature thresholdrequired to start the ORC system 102, the coolant is cooled by thecooler 128 prior to recirculating into the airend 120.

In example embodiments, the contact-cooled airend may include more thanone airend stage. An intercooler may be disposed between each of theairend stages to cool the pressurized working fluid and coolant mixturebefore entering the next airend stage to be further pressurized. Theturbocharged fluid compression system 100 is not limited to having onlyone airend 120.

FIG. 3 is a schematic of an example embodiment of the turbocharged fluidcompressor system 200, where a coolant-free fluid compressor system 204includes a coolant-free airend 220. Coolant-free airend 220 includes afirst airend stage S1, a second airend stage S2, an intercooler 222 andan aftercooler 224. Other example embodiments of the coolant-freecompressor system 204 may employ a different number of airend stages.Turbocharged fluid compressor system 200 includes two evaporators: afirst evaporator 236, located downstream from the first airend stage S1,acting as a pre-intercooler, and a second evaporator 238, locateddownstream from the second airend stage S2, acting as a pre-aftercooler.

The organic fluid in ORC system 202 is moved by pump 206. An organicfluid flow stream 207 is then split into a first flow stream 208 and asecond flow stream 209. The first flow stream 208 passes into the firstevaporator 236, where the organic fluid is evaporated. After splittingfrom the first flow stream 208, the second flow stream 209 is directedto the second evaporator 238, where the organic fluid is evaporated.First flow stream 208 and second flow stream 209 merge back togetherinto the same organic fluid flow stream 207 upstream of the turbinesection 212 of turbocharger 210. The turbine section 212 extracts theenergy from the organic fluid vapor and converts it into kinetic energy,driving the compressor section 214 of the turbocharger 210.

The organic fluid is delivered from the turbine section 212 of theturbocharger 210 into condenser 216, where it condenses. The organicfluid is pumped back by pump 206, and splits prior to entering firstevaporator 236 and second evaporator 238, where it absorbs the wasteheat from the working fluid as it exits the first compression stage S1and second compression stage S2 respectively.

The working fluid is pre-compressed by compressor section 214 ofturbocharger 210 prior to entering the first airend stage S1 ofcoolant-free airend 220. As the pressure of the working fluid isincreased, its temperature increases. Upon leaving first airend stageS1, the working fluid enters the first evaporator 236. The organic fluidin first evaporator 236 absorbs the waste heat from the working fluid,evaporating as a result. The pre-cooled working fluid then flows intointercooler 222, where its temperature is further decreased beforeentering second airend stage S2 of coolant-free airend 220. The workingfluid is compressed further, increasing in temperature once again. Thecompressed working fluid flows into the second evaporator 238 acting asa pre-aftercooler. The organic fluid in second evaporator 236 absorbsthe waste heat from the working fluid, evaporating as a result. Thepre-cooled working fluid then flows into aftercooler 224, where itstemperature is further decreased prior to exiting the turbocharged fluidcompressor system 200 for delivery. As waste heat is produced inrelatively equal amounts in first and second airend stages S1 and S2, itis possible to have first evaporator 236 and second evaporator 238working in parallel, evaporating the organic fluid flowing through theORC system 202.

Turbocharged fluid compressor system 200 may include a coolant/lubricantcirculation system where a coolant/lubricant cools and/or lubricates theworking fluid without mixing with the working fluid in neither of theairend stages S1 and S2. The coolant/lubricant may absorb heat from theworking fluid as it cools/lubricates the working fluid. In exampleembodiments, the heat absorbed by the coolant/lubricant may be used topreheat the ORC fluid before the ORC fluid enters the pre-intercooler208 or the pre-aftercooler 238. The hot coolant/lubricant may also becirculated to a third evaporator (not shown) that absorbs the excessheat absorbed by the coolant/lubricant before the coolant/lubricantrecirculates.

In example embodiments, the intercooler 222 and the aftercooler 224 maybe reduced in size, as the majority of the excess heat in the workingfluid is absorbed by the evaporating organic fluid in first and secondevaporators. In example embodiments, the first evaporator 236 and thesecond evaporator 238 may replace intercooler 222 and aftercooler 224,respectively.

The thermal efficiency of the ORC system varies depending on the chosenorganic compound used as the waste heat recovery fluid, as differentorganic compounds have different boiling point temperatures. Examples oforganic compounds include but are not limited to HDR-14, isobutane,isopentane, R245fa, SES36, R227ea, among others. For example, inturbocharged fluid compressor system 200, the working fluid compressedby coolant-free airend 220 has a higher discharge temperature than thedischarge temperature of the working fluid compressed by contact-cooledairend 120 in turbocharged fluid compressor system 100. The organicfluid used in turbocharged fluid compressor system 100 may be an organiccompound (e.g., HDR-14) suitable for evaporating at a lower temperaturethan the evaporating temperature of the organic compound (e.g.,isobutane) used in turbocharged fluid compression system 200. It shouldbe understood that the selection of the waste heat recovery fluid maychange based on specific configurations, parameters and requirements ofeach application.

The turbocharged fluid compressor system may be retrofitted intoexisting compression systems. The application of the turbocharged fluidcompressor system is not limited to fluid compression systems, as anyequipment having a compression application with waste heat availablefrom within or outside the compression system may benefit from theincreased efficiency as a result of the turbocharged compressor system.Other applications include but are not limited to HVAC systems,refrigeration systems, gas turbines, etc.

While the subject matter has been illustrated and described in detail inthe drawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly the preferred embodiments have been shown and described and thatall changes and modifications that come within the spirit of the subjectmatters are desired to be protected. It should be understood that whilethe use of words such as preferable, preferably, preferred or morepreferred utilized in the description above indicate that the feature sodescribed may be more desirable, it nonetheless may not be necessary andembodiments lacking the same may be contemplated as within the scope ofthe subject matter, the scope being defined by the claims that follow.In reading the claims, it is intended that when words such as “a,” “an,”“at least one,” or “at least one portion” are used there is no intentionto limit the claim to only one item unless specifically stated to thecontrary in the claim. When the language “at least a portion” and/or “aportion” is used the item can include a portion and/or the entire itemunless specifically stated to the contrary. Unless specified or limitedotherwise, the terms “mounted,” “connected,” “supported,” and “coupled”and variations thereof are used broadly and encompass both direct andindirect mountings, connections, supports, and couplings. Further,“connected” and “coupled” are not restricted to physical or mechanicalconnections or couplings.

Although the subject matter has been described in language specific tostructural features and/or process operations, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

What is claimed is:
 1. A turbocharged fluid compressor system forcompressing a working fluid comprising: an Organic Rankine Cycle (ORC)system operable with an organic fluid, the ORC system including: atleast one evaporator evaporating the organic fluid into an organic fluidvapor, a turbocharger having a turbine section and a compressor section,the turbine section receiving and expanding the organic fluid vapor todrive the compressor section, wherein the compressor sectionpre-compresses the working fluid, and a condenser configured to condensethe organic fluid vapor; and a fluid compressor system operable toreceive the pre-compressed working fluid from the compressor section ofthe turbocharger and further compress the working fluid, the fluidcompressor system producing heat, and wherein the at least oneevaporator further recovers the heat produced by the fluid compressorsystem to evaporate the organic fluid in the ORC system.
 2. Theturbocharged fluid compressor system of claim 1, where thepre-compressed working fluid is cooled by a heat-dissipating devicebefore entering the fluid compressor system.
 3. The turbocharged fluidcompressor system of claim 2, where the heat-dissipating device is afinned tube.
 4. The turbocharged fluid compressor system of claim 1,where the at least one evaporator is a brazed plate heat exchanger. 5.The turbocharged fluid compressor system of claim 1, where the fluidcompressor system includes a contact-cooled airend, the contact-cooledairend compressing the working fluid.
 6. The turbocharged fluidcompressor system of claim 5, where the compressor system includes acoolant circulation system, the coolant circulation system including acoolant separator tank in fluid communication with the contact-cooledairend to separate coolant injected into the working fluid duringcompression, a primary temperature control valve (TCV), a secondarytemperature control valve, and a cooler to cool the coolant prior torecirculation.
 7. The turbocharged fluid compressor system of claim 6,where the primary TCV selectably directs the coolant from the coolantseparator tank to the at least one evaporator.
 8. The turbocharged fluidcompressor system of claim 7, where the organic fluid in the at leastone evaporator evaporates by absorbing excess heat from the coolant. 9.The turbocharged fluid compressor system of claim 6, where the primaryTCV selectably directs the coolant from the secondary TCV to thecontact-cooled airend.
 10. The turbocharged fluid compressor system ofclaim 6, where the secondary TCV selectably directs the coolant from theat least one evaporator to the cooler.
 11. The turbocharged fluidcompressor system of claim 6, where the secondary TCV selectably directsthe coolant from the at least one evaporator to the primary TCV.
 12. Theturbocharged fluid compressor system of claim 6, where the secondary TCVselectably directs the coolant from the cooler to the primary TCV. 13.The turbocharged fluid compressor system of claim 5, where the fluidcompressor system includes a coolant-free compressor having a firstcompressor stage, a second compressor stage, an intercooler between thefirst compressor stage and the second compressor stage, and anaftercooler located downstream of the second compressor stage.
 14. Theturbocharged fluid compressor system of claim 13, where the ORC systemincludes a first evaporator and a second evaporator.
 15. Theturbocharged fluid compressor system of claim 14, where the firstevaporator serves as a pre-intercooler located between the firstcompressor stage and the intercooler.
 16. The turbocharged fluidcompressor system of claim 14, where the second evaporator serves as apre-aftercooler located between the second compressor stage and theaftercooler.
 17. A turbocharged fluid compressor system for compressinga working fluid comprising: a waste heat recovery system operable with awaste heat recovery fluid including: at least one evaporator evaporatingthe waste heat recovery fluid into a waste heat recovery fluid vapor, aturbocharger having a turbine section and a compressor section, theturbine section receiving and expanding the waste heat recovery fluidvapor to drive the compressor section, wherein the compressor sectionpre-compresses the working fluid, and a condenser configured to condensethe waste heat recovery fluid vapor; and a fluid compressor systemoperable to receive the pre-compressed working fluid from the compressorsection of the turbocharger and further compress the working fluid, thefluid compressor system producing waste heat, and wherein the at leastone evaporator further recovers the waste heat produced by the fluidcompressor system to evaporate the waste heat recovery fluid in thewaste heat recovery system.
 18. The turbocharged fluid compressor systemof claim 17, where the waste heat recovery system is a Rankine cyclesystem.
 19. The turbocharged fluid compressor system of claim 18, wherethe waste heat recovery system is an organic Rankine cycle (ORC) system,and the waste heat recovery fluid is an organic fluid.
 20. Aturbocharged system comprising: a waste heat recovery system operablewith a waste heat recovery fluid including: at least one evaporator forevaporating the waste heat recovery fluid into a waste heat recoveryfluid vapor, a turbocharger having a turbine section and a compressorsection, the turbine section receiving and expanding the waste heatrecovery fluid vapor to drive the compressor section, wherein thecompressor section pre-compresses a working fluid, and a condenser forcondensing the waste heat recovery fluid vapor, wherein the condensedwaste heat recovery fluid is returned into the at least one evaporator;and a fluid compressor system having an airend operable to receive thepre-compressed working fluid from the compressor section of theturbocharger and further compress the working fluid, the fluidcompressor system producing heat, and wherein the at least oneevaporator further recovers the waste heat produced by the fluidcompressor system to evaporate the waste heat recovery fluid in thewaste heat recovery system.